scholarly journals Nonlinear Distortion Cancellation using Predistorter in MIMO-GFDM Systems

Electronics ◽  
2019 ◽  
Vol 8 (6) ◽  
pp. 620
Author(s):  
Ari Endang Jayati ◽  
Wirawan ◽  
Titiek Suryani ◽  
Endroyono

Generalized frequency division multiplexing (GFDM) with offset quadrature amplitude modulation (OQAM) is an alternative non-orthogonal modulation scheme for future generation wireless broadband systems. The nonlinearity of high power amplifiers (HPAs) has a very significant effect on the performance of GFDM systems. In this paper, we investigate the effects of nonlinear distortion on the multiple-input multiple-output (MIMO)-GFDM system when the signal is passed the HPA, which is modeled with amplitude and phase distortion. The effects of nonlinear distortion due to the HPA include amplitude distortion, phase distortion, and the spread of signal constellations. These effects also produce harmonic signals and intermodulation outside the frequency band which results in spectral spread. This will then reduce the performance of the MIMO-GFDM system. The contributions of this paper concern three key areas. Firstly, we investigate the effects of nonlinear distortion on the MIMO-GFDM system. We also derive the new closed-form expression bit error rate (BER) in MIMO-GFDM systems that use a memoryless HPA, which is modeled using the Saleh model when passed through the additive white Gaussian noise (AWGN) channel. This model was chosen because it is simple and has AM/AM and AM/PM curves. Secondly, we propose the application of techniques for the linearization of each HPA predistorter on the transmitter side of the MIMO-GFDM system separately. This predistorter is able to compensate for nonlinear distortion caused by the HPA without memory operating in the saturation region. The main contribution of this paper is to investigate the predistorter, which can linearize nonlinear distortion in MIMO-GFDM transmitters. The performance of the proposed scheme is evaluated in terms of spectrum analysis, PAPR analysis, a constellation diagram, and bit error rate (BER) analysis. The simulation results show that the proposed predistorter design succeeds in compensating for nonlinear distortions caused by the HPA for large input back-off (IBO) values.

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Hocine Fekih ◽  
Boubakar Seddik Bouazza ◽  
Keltoum Nouri

AbstractRecently, using iterative decoding algorithms to achieve an interesting bit error rate for spectrally efficient modulation become a necessity for optical transmission, in this paper, we propose a coded modulation scheme based on bit interleaving circular recursive systematic convolutional (CRSC) code and 16-QAM modulation. The proposal system considered as a serial concatenation of a channel encoder, a bit interleaver and M-ary modulator can be flexible easy to implement using a short code length. For a spectral efficiency $\eta =3\text{bit}/s/Hz$, the coding gain at a bit error rate of 10−6 is about 8 dB.


2021 ◽  
pp. 108-114
Author(s):  
D.D. Privalov

The sampling rate at a given bit rate is a requirement for the speed of digital signal processors. In this regard, it is necessary to strive to reduce it in the development of electronic devices, especially portable ones. However, this can lead to an increase in the bit error rate during signal detection. Therefore, it is important to determine the degradation of signal detection with decreasing sampling frequency and to develop practical recommendations to ensure the specified quality of communication. The aim of the article is to study the influence of sampling frequency and interpolation on the bit error rate of GMSK Signal. The article considers the incoherent detection of a GMSK signal in a channel with additive white Gaussian noise, taking into account the influence of the clock synchronization error. Numerical results are presented that characterize an increase in the bit error rate with a decrease in the signal sampling frequency. It is shown that when using the cubic Farrow interpolator, there is no significant degradation in the bit error probability. The minimum number of samples per symbol is determined, at which the bit error rate is close to the theoretical values in the absence of synchronization error. The presented results can be used in development of wireless data transmission systems.


Jurnal INKOM ◽  
2014 ◽  
Vol 8 (1) ◽  
pp. 37
Author(s):  
Rika Sustika ◽  
Oka Mahendra

Pada tulisan ini, dievaluasi performansi skema modulasi MFSK (M-ary Frequency Shift Keying) untuk aplikasi pengiriman data melalui kanal suara GSM (Global System for Mobile Communication). Parameter yang dievaluasi berupa kesalahan bit trasmisi yang dinyatakan dengan laju kesalahan bit atau bit error rate (BER). Evaluasi ini dilakukan untuk menentukan besarnya orde M yang akan dipilih pada aplikasi pengiriman data digital melalui kanal suara GSM. Pada proses simulasi, data digital dikodekan menjadi simbol-simbol lalu dimodulasi menggunakan modulator MFSK menjadi data menyerupai pembicaraan (suara). Suara yang dihasilkan dikodekan dengan algoritma CELP (Code Excited Linear Prediction), kemudian dikirimkan melalui udara yang dimodelkan sebagai kanal AWGN (Additive White Gaussian Noise). Di sisi penerima, sinyal terima yang menyerupai suara ini didemodulasi dan dikonversi kembali menjadi data digital. Dari simulasi menggunakan Eb/No (signal to noise ratio) sebesar 6 dB, diperoleh laju bit 2,5 kbps dengan BER 2,01 x 10-3 untuk M=4, 2,22 x 10-3 untuk M=8, dan 1,87 x 10-3 untuk M=16.


2017 ◽  
Vol 18 (2) ◽  
Author(s):  
ION POPA

<p>This paper follows the study of bit error rate evolution in a mobile communications system using DS – CDMA (Direct Sequence – Code Division Multiple Access) technology. We have assessed the bit error rate (BER) based on the signal/noise ratio, Eb/N0, and the number of users in the system. For this purpose, we have used M sequence and Orthogonal Gold sequence and the AWGN (Additive white Gaussian noise) transmission medium<strong>.</strong></p>


The digital communication technologies have gained immense significance as it provides secure and error free services. One of the major advantages of digital communication is that they are much resistant to transmitted as well as interpreted errors. For ensuring the security of data, the most suitable method is to use spread spectrum technique. The spread spectrum technique has gained immense popularity for use in various systems as the spreading of the spectral bandwidth offer many advantages, including the establishment of secure communications, increasing resistance to interference, noise rejection, and so on. The signals which are modulated by using these techniques cannot be jammed and are very hard to interfere. This paper presents the results of investigation of BPSK based direct sequence spread spectrum systems for Additive White Gaussian Noise (AWGN) and undersea channels. The bit error rate performance of BPSK based direct sequence spread spectrum systems has been simulated for the AWGN channel and the results have been plotted.


Author(s):  
Manoj Kumar A ◽  
R V Nadagouda ◽  
R Jegan

Bit Error Rate (BER) is a principle measure of data transmission link performance. BER tester (BERT) consists of a Pattern Generator and an Analyzer that can be set to the same pattern. The payload data transmitted from the spacecraft consists of one, two or three channels per carrier based on the modulation scheme. The traditional equipments can do BER analysis for only one channel at a time. In order to support multichannel BER analysis, a Personal Computer (PC) based system is designed and implemented in Altera Stratix II (EP2S130F1508C5N) FPGA. Ethernet is configured using WIZnet 5300 (Ethernet Controller) and it is used for communication between FPGA and PC with an application. Application is used to transmit the Pattern Generator’s configurations from PC to FPGA and to receive Analyzer’s status. Packet processing is done for this communication using User Datagram protocol (UDP). On the whole, traditional equipments are replaced by the designed and implemented bit error rate tester.


2015 ◽  
Vol 727-728 ◽  
pp. 809-812
Author(s):  
Bo Qin Xu ◽  
Zhu Jun Zhang ◽  
Jun Wei Hu

Mud pulse telemetry (MPT) transmits data from borehole to surface during the drilling process. Pressure wave is generated in the drilling channel and is used as carrier of the downhole data. Through numerical simulation, this paper analyzes the bit error rate (BER) of mud pulse telemetry under different signal to noise ratio (SNR) based on on-off keying (OOK) modulation scheme. By observing the effect of waveform error on BER, the allowed variation ranges in signal amplitude and period are obtained.


Sign in / Sign up

Export Citation Format

Share Document